Remanence properties and magntization reversal mechanism of Fe nanowire arrays with diameters 16nm and 130 nm are studies. Isothermal remanent magnetization curves show that the contribution of irreversible magnetization decreases when the diameter changes from 16nm to 130nm. The remanence coercivities of these nanowires obtained in dc-demagnetization curve are about 2400 Oe and 800 Oe, respectively. The magnetization reversal mechanism is different in these two samples. For the nanowire array with diameter 16nm, both the mucleation and the pinning have effects on magnetization reversal mechanism, and the pinning field (about 2500 Oe) is larger than the mucleation field (about 2200 Oe). However, for the nanowire array with diameter 130nm, the magnetization reversal mechanism is dominated by the pinning effect of domain walls.

Fe29Co71 and Fe19Bi81 antidot arrays, with different ajmensions, are prepared with the rf magntron supttering method onto the porous alumina substrate. The size and shape of antidot arrays are characterized by scanning electron microscopy. The glancing angle x-ray diffreaction patterns of Fe29Ci71 and Fe19Ni81 antidot arrays indicate the bcc and fcc structures, respectively. The coercivities of both the alloys show abnormal thickness dependence, whick are discussed qualitatively by considering the pinning and the thickness effect to the films.

Nanowire arrays of the alloy, Fe0.68Ni0.32, with different nanowire diameters have been fabricated by the electrochemical deposition method.X-ray diffraction and M.ossbauer spectroscopy were employed to characterize the size effect on the structure and micro-magnetic properties of the nanowire array, respectively.The Fe0.68Ni0.32 arrays with different diameters are stabilized in a BCC structure with a [110] texture oriented along the long axis of the nanowires.The M.ossbauer spectra of the nanowire arrays with smaller diameters show an absence of the second and fifth peaks, which then emerge with increasing diameter.The size effects on the hyperfine parameters are discussed.

Dynamic magnetic susceptibilities of high-aspect-ratio permalloylike nanorings outer diameter 20nm, inner diameter 12nm, length L range 12-500nm are studied using three-dimensional micromagnetic simulations. The investigated systems show two major resonance modes associated with volume and shape resonance modes, corresponding to low and high resonance frequencies, respectively. When L is below 40nm, only the shape resonance mode is seen with a frequency predicted using the Kittel's equation and demagnetization factor calculated for a ring. At sufficiently large L, the frequency of the volume mode converges to that of the Kittel prediction. For other lengths, however, neither the low resonance frequency nor the high resonance frequency agrees with the Kittel's equation. A weighted average resonance frequency fa i that contains two major modes is introduced and shows the same trend as the results predicted by the Kittel's equation for all lengths. The frequencies of volume and shape resonance modes have also been investigated by changing the exchange stiffness constant A and the saturation magnetization Ms.

用交流电化学沉积方法在阳极氧化铝模板中成功地制备了直径约16nm，长度4μm的Fe1-xNix（0<x≤0.32）合金纳米线。在该成分范围内合金纳米线的结构均为bcc结构，且表现出（110）面的择优取向。穆斯堡尔谱的研究表明由于存在很大的形状各向异性，纳米线内部铁原子的磁矩取向均沿着纳米线的方向。而且随着镍含量的增加，超精细磁场平缓变化，与块体中的变化趋势一致。